A utility knife that has a knife housing and a blade carried by a blade support is known from obvious prior use. The blade support can be moved between a safety position where the blade is situated in the housing, inaccessible to the user, and a cutting position where the blade projects out of the housing.
Such a blade was used for cutting bags open, for example, which are hanging from a conveyor and contain bulk material, for example. In this connection, there is the risk that the bag will come loose, fall, and injure the user of the knife.